Lubricant and fuel compositions

ABSTRACT

Hydrocarbyl acid phosphate salts of ditetrahydropyrimidines and petroleum hydrocarbon compositions containing the same. The salts are formed by neutralizing with a hydrocarbyl acid orthophosphate at least 25 percent of the basic nitrogens of the ditetrahydropyrimidine. Petroleum hydrocarbon compositions containing these salts exhibit desirable properties such as enhanced corrosion resistance and improved detergency. Gasoline compositions containing the salts are also characterized by improved carburetor anti-icing characteristics.

United/States Patent [1 1 Robinson et al.

i111 3,844,957 [451 Oct. 29, 1974 LUBRICANT AND FUEL COMPOSITIONS Inventors: Franklin H. Robinson, North Brunswick; Marvin S. Rakow, East Brunswick; Paul M. Kerschner, Trenton, all of NJ.

Cities Service Oil Company, Tulsa, Okla.

Filed: July 30, 1971 Appl. No.: 167,808

Assignee:

U.S. Cl 252/32.5, 44/DIG. 1, 44/63, 252/389 A Int. Cl. Cl0m 3/40, ClOm 1/46 Field of Search 252/32.5, 389; 44/DIG. l,

References Cited UNITED STATES PATENTS 2/1967 LeSuer 252/32.5 Latos et al..... 2521325 Latos 252/32.5

3,484,374 12/1969 Cyba 252/32.S 3,502,677 3/1970 LeSuer...'. 252/32.5 3,585,210 6/1971 Redmore 44/63 Primary Examiner-Patrick P. Garvin Assistant Examiner-I. Vaughn Attorney, Agent, or Firm-J. W. Carpenter; G. L.

Rushton; E. T. Yates ABSTRACT rahydropyrimidine. Petroleum hydrocarbon compositions containing these salts exhibit desirable properties such as enhanced corrosion resistance and improved detergency. Gasoline compositions containing the salts are also characterized by improved carburetor antiicing characteristics.

3 Claims, N0 Drawings LUBRICANT AND FUEL COMPOSITIONS BACKGROUND OF THE INVENTION Normally liquid petroleum hydrocarbon products often require additives to improve their performance characteristics. Thus, in fuels such as gasoline, diesel fuel, jet fuel, and burner fuel, various additives are employed to assist in maintaining cleanliness in the carburetor and fuel intake system and to prevent carburetor icing as well as to inhibit rust. In hydrocarbon lubricating oils, additives are often employed to enhance the detergency and anti-corrosion properties. The additives vary in effectiveness, and it is often necessary to use a number of additives in a single composition.

Many additives for petroleum hydrocarbon products are only marginally soluble in hydrocarbons. Furthermore, they are often employed in concentrations that approach their limits of solubility. As a result, hydrocarbon compositions containing such additives often exhibit poor stability and, as a result, on standing the additive may precipitate.

SUMMARY OF THE INVENTION Desirable properties such as enhanced detergency and anti-corrosion characteristics are imparted to petroleum hydrocarbon products by the incorporation therein of hydrocarbon-soluble hydrocarbyl acid orthophosphate salts of ditetrahydropyrimidines. When the petroleumhydrocarbon is a fuel such as gasoline, in addition to improved detergency and anti-corrosionproperties, the gasoline'composition is characterized by enhanced carburetor anti-icing properties. Thus, petroleum hydrocarbon compositions of this invention used to fuel or lubricate internal combustion engines assist in maintaining cleanliness in the carburetor and fuel intake system and in preventing carburetor icingas well as in inhibiting corrosion. I

It is, therefore, an object of this inventionto provide additives which, when incorporated in normally liquid petroleum hydrocarbon products, impart desirable properties thereto.

It is another object of this invention toprovide additives which are readily soluble in normally liquid hydro-. carbon products to produce stable solutions.

Another object of this invention is to provide normally liquid petroleum hydrocarbon compositions having enhanced detergency and anti-corrosion properties.

wherein R is a hydrocarbylene group and R is a hydrocarbyl group; and normally liquid petroleum hydrocarbon compositions comprising a major proportion of a normally liquid petroleum hydrocarbon product and a minor proportion of the above hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine.

Normally liquid petroleum hydrocarbon product compositions such as lubricating oils and fuels containing the additives ofthis invention exhibitsuch desirable properties as enhanced detergency and anti-corrosion characteristics. In addition, gasoline compositions containing the inventive additives have carburetor antiicing -properties. Accordingly, engines that are fueled or lubricatedby hydrocarbon compositions of this invention are characterized by clean carburetor and fuel intake systems .as well: as reduced corrosion. Furthermore, the. good solubility of the additives of this inventionin liquid petroleum hydrocarbon products ensures stability with little tendency toward gum formation. Another advantage of the additives of this invention is their ability to impart desirable properties to liquid petroleum hydrocarbon products when used at low concentrationswhich 'makes them economically attractive. Other advantages :of this invention will be apparent from the following detailed description.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The normally liquid petroleum hydrocarbon compositionstof this invention are prepared by incorporating intoa majorproportionof a normally liquid petroleum hydrocarbon product a minorporportion of an additive which is a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine. Examples of normally liquid petroleum (hydrocarbon products that have desirable, properties imparted thereto by the additives of this invention are gasoline, jet fuel, diesel fuel, burner fuel, and lubricating oil.

Thenovel additives of this invention are prepared by reacting a hydrocarbyl acid orthophosphate with a ditetrahydropyrimidine whereby at least 25 percent of the basicnitrogens of said ditetrahydropyrimidine are convertedto the'hydrocarbyl acid orthophosphate salt. Theditetrahydropyrimidines, having the general formula whereinR is ahydrocarbylene group and R is a hydrocarbylgroup, maybe prepared'by condensing l mole of.a dicarboxylic acid or dicarboxylic acid anhydride with 2 moles of an N-hydrocarbyl-l ,3- propylenediamine. In the case where a dicarboxylic acid anhydride is employed, 3 moles of water are eliminated: v

R and R are as defined above. In the case where a dicarboxylic acid is used, 4 moles of water are elimi- Again, R and R are as defmed above.

The dicarboxylic acid or dicarboxylic acid anhydride which is used in the preparation of the ditetrahydropyrimidine has a hydrocarbylene group R that contains about 2 to 34 carbons and preferably about 2 to carbons. R may be aliphatic, aromatic or naphthenic, or it may contain various mixtures of aliphatic, aromatic and naphthenic segments. ,Aliphatic and naphthenic segments may be either saturated or unsaturated. Examples of suitable dicarboxylic acids and dicarboxylic acid anhydrides are maleic anhydride, maleic acid; succinic acid; succinic anhydride; glutaric acid; glutaric anhydride; adipic acid; terephthalic acid; l.4-cyclohexanedicarboxylic acid; l,l()- dicarboxydecane'. l.lS-dicarboxyoctandecane; 1,8- dicarboxyoctane; and a dimer acid produced by the dimcrization of a polyunsaturated C monocarboxylic fatty acid to produce an unsaturated C dicarboxylic acid wherein R contains 34 carbons. It is preferred that the ditetrahydropyrimidine be prepared from maleic anhydride or maleic acid in which case R is vinylene.

The N-hydrocarbyl-l,3-propylenediamine which is condensed with the dicarboxylic acid or dicarboxylic acid anhydride to form the ditetrahydropyrimidine has a hydrocarbyl group R that contains about 6 to carbons and preferably about 10 to 25 carbons. R may be aliphatic. aromatic or naphthenic. or it may contain various mixtures of aliphatic, aromatic and naphthenic segments. Aliphatic and naphthenic segments may be either saturated or unsaturated. Examples of suitable R groups are hexyl, cyclohexyl, phenyl, p-tolyl, triacontyl. tricosyl, eicosyl. decyl. dodecyl, 4- butylcyclohexyl, stearyl, oleyl. and cyclooctenyl. The preferred hydrocarbyl group R is tallowyl, hence the preferred propylenediamine is N-tallowy|-l,3- propylenediamine.

The hydrocarbyl acid orthophosphate which is reacted with the ditetrahydropyrimidine to form a salt may be a dihydrocarbyl acid orthophosphate, a hydrocarbyl diacid orthophosphate or preferably a mixture of a dihydrocarbyl acid orthophosphate and a hydrocarbyl diacid orthophosphate. The hydrocarbyl portions contain from about i to about 15 carbons and preferably from about 3 to about 10 carbons. in the case of dihydrocarbyl acid orthophosphates and mixtures of dihydrocarbyl acid orthophosphates and hydrocarbyl diacid orthophosphates, the hydrocarbyl groups may be the same or different. The hydrocarbyl portions may be aliphatic, aromatic or naphthenic or they may contain various mixtures of aliphatic. aromatic and naphthenic segments. Aliphaticand naphthenic segments may be either saturated or unsaturated. lt is preferred that the hydrocarbyl portions be aliphatic.

The ratio of hydrocarbyl acid orthophosphate to the ditetrahydropyrimidine is such at least about 25 percent of the basic nitrogens of the ditetrahydropyrimidine are converted to the hydrocarbyl acid orthophosphate salt. While about 25 percent to about 100 percent of the basic nitrogens may be converted to the hydrocarbyl acid orthophosphate salt, it is preferred that about percent to about 90 percent of the basic nitrogens be converted to the salt. However, an excess of hydrocarbyl acid orthophosphate may be present in the case where 100 percent of the basic nitrogens are converted to the salt.

Examples of hydrocarbyl acid orthophosphates are cyclohexyl diacid orthophosphate, diphenyl acid orthophosphate, methyldecyl acid orthophosphate, pentadecyl diacid orthophosphate, dipropyl acid orthophosphate, heptyl diacid orthophosphate, isooctyl diacid orthophosphate, and diisooctyl acid orthophosphate. The preferred hydrocarbyl acid orthophosphate a mixture of isooctyl diacid orthophosphate and diisooctyl acid orthophosphate. Most' preferred is a mixture of about 65 weight percent diisooctyl acid orthophosphate and about 35 weight percent of isooctyl diacid orthophosphate.

A particularly preferred hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine is thus the salt of a ditetrahydropyrimidine prepared by the condensation of 1 mole of maleic acid or maleic anhydride with 2 moles of N-tallowyl-l,3-propylenediamine and having the structural formula acid orthophosphate and about 35 weight percent isooctyl diacid orthophosphate.

While the concentration of the hydrocarbyl acid orthophosphate salt of the ditetrahydropyrimidine additive of this invention in petroleum hydrocarbon products, such as fuels and lubricating oils, may be varied over a broad range, petroleum hydrocarbon compositions containing about i to 250 pounds of additive per thousand barrels (PTB) of the composition are generally used. However, hydrocarbon fuel and lubricating oil compositions containing from about 3 to PTB of additive are preferred.

The efficacy of the additives of this invention in petroleum hydrocarbon product compositions is determined by subjecting said compositions to one or more of the following tests. The test procedures are as follows.

CARBURETOR DETERGENCY TEST:

Engine blow-by contaminants are generated in an engine and collected in a flask. At the end of the collecting period the water phase is separated from the fuel phase, the latter being discarded. The water phase of the contaminants is used for the carburetor detergency evaluations.

The carburetor detergency test is run on a Cooperative Lubricants Research (CLR) engine, a single cylinand reference fuels are tested with the same batch of m contaminants.

At the conclusion of the 3 hour run, the 200 mesh screen is removed and evaluated for contaminant accumulation. The reflectance of the screen, determined by means of a reflectance meter, is a measure of the amount of deposits accumulated on the screen. The higher the reflectance, the cleaner the screen, i.e., the lower the accumulation of deposits. I

The effectiveness of an additive is represented as th ratio. expressed as a percentage, of the average screen reflectance for the fuel containing the additive to the average screen reflectance for a reference fuel containing a commercially available carburetor detergent additive at a concentration of pounds per thousand (PTB). Thus, a fuel composition containingan experimental additive that equals the performance of'the reference fuel will have an effectiveness of 100 percent, an experimental fuel that performs at a lower level than the reference fuel will have an effectiveness of lessthan 100 percent. and an experimental fuel that'performs at a higher level than the reference fuel will have'an effectiveness of greater than 100 percent.

CARBURETOR ANTl-ICING TESTQ The test is run on a CLR single cylinder engine cou' pled to a speed control dynamometer. The engine is fitted with a special, thermally-isolated carburetor with external float bowls; no idle fuel system is used. The carburetor has an adjustable main jet and the throttle body is constructed of glass or clear plastic so icing can be confirmed by visual inspection. A temperature and humidity control system supplies inlet air to the carburetor at the desired conditions and also to a glass or clear plastic box enclosing the carburetor.

All anti-icing additives are evaluated in a blended base fuel composed of volume percent of ASTM isooctane and 75 volume percent of precipitation naphtha and containing 1.5 ml./gal. of tetraethyl lead. Also present are a scavenger, metal deactivator, and an antioxidant. A non-icing purge fuel consisting of the base fuel containing 5.5 percent of isopropyl alcohol is used in the test. The anti-icing properties of fuel compositions containing additives of this invention are compared to those of the base fuel containing no anti-icing additive.

lce formation on the throttle plate of the carburetor is measured by an increase in manifold vacuum caused by a choking of the engine by the ice formation. The

time in seconds for the manifold vacuum to increase 2.0 inches of mercury is recorded as time toice with the fuel which is being-evaluated. An increase in manifold vacuum of 2.0 inches of mercury is defined assevere ice.

Engine operating conditions are set so as to cause a reference fuel, Le, a base fuel containing a reference anti-icing additive, to ice sufficiently to cause a 2.0 inch manifold vacuum increase in 40 to 50 seconds. When these conditions are set, the base fuel containing no anti-icing additive will ice to the same extent in 18 to 20 seconds. Once these operating conditions have been achieved. the anti-icing characteristics of base fuel containing the experimental additives can be evaluated.

In running the test on a fuel composition containing an experimental additive, once ice severe enough to raise the manifold vacuum 2.0 inches of mercury has formed, the carburetor is switched to the purge fuel which removes the ice. After 50 seconds to allow for ice removal and engine stabilization, the carburetor is switched back to the experimental fuel. The above procedure is repeated until five runs on the experimental fuel have been :made, the timesfor a manifold vacuum increase of 2.0 inches of mercury being noted. The times of the five runs are then'averaged. Either a base fuel or a reference fuel is run after every two experimental additive runs.

In addition to the foregoing, the rust inhibition properties of the inventive additives are determined by the ASTM D-665 andthe Mil-250l7-B procedures.

The inventionwill be further illustrated by the following specific examples.

EXAMPLE 1 In a flask fitted with a stirrer, thermometer, reflux condenser, and Dean-Stark trap and containing toluene, as diluent are placed 148 g. of a dimeracid which is produced by the dimerization of a polyunsaturated C monocarboxylic fatty acid to produce an unsaturated C dicarboxylic acid and 180.8 g. of N-.ta1lowyl-1,3- propyl en'ediamine. The reaction mixture is stirred under reflux at 175C and water of condensation collected in the Dean-Stark trap. The amount of water collectedis' 20 ml.; the theoretical amount of water for the formation of the ditetrahydropyrimidine is 22.3 ml. The toluene is then removed by distillation to leave a residue of the ditetrahydropyrimidine,

The hydrocarbyl acid orthophosphate salt of the above ditetrahydropyrimidene is prepared by adding to 6.75 g. of said ditetrahydropyrimidine 3.25 g. of a mixture comprising about weight percent diisooctyl acid orthophosphate and about 35 weight percent isooctyl diacid orthophosphate. The pH of the salt is 7.0, corresponding to percent of the basic nitrogens of s the ditetrahydropyrimidine being converted to the salt. This salt is designated additive a.

EXAMPLE n being converted to the salt. This saltis designated additive b.

T0694 g. of theditetrahydropyrimidine prepared by the above reaction are added 3.06 g. of the same mixture of isooctyl acid orthophosphates as are used above. The pH of the resultant salt is 7.5, corresponding to 63 percent of the basic nitrogens of the ditetrahydropyrimidine being converted to the salt. This salt is designated additive c.

EXAMPLE lll Gasoline compositions are prepared by dissolving the hydrocarbyl acid orthophosphate salts or ditetrahydropyrimidines designated additives a and b in a base gasoline containing 3 ml. ofTEL/gal. and the compositions are subjected to the carburetor detergency test. For comparison purposes, a base leaded gasoline containing no other additive than 3 ml. of TEL/gal. and a leaded (3 ml. of TEL/gal.)gasoline composition containing a commercially available multi-functional additive. i.e.. DMA-4 manufactured by the Du Pont Company and containing 80 percent of active ingredient and 20 percent kerosene are also subjected to the carburetor detergency test. The make-up of each gasoline composition and its screen reflectance as well as its percent effectiveness as determined by the average screen reflectance are given in Table l. The gasoline composition containing 15 PTB of DMA-4 has been assigned an effectiveness of 100 percent and all results are relative to this reference. Each result is the average of a number of determinations.

TABLE I Concentration Screen "/1 Additive P B Reflectance Effectiveness 5. I 60 DMA-4 l5 8.5 I a 15 l 7.4 205 b l 27.2 320 It is seen from Table I that gasoline compositions containing additives of this invention have excellent carburetor detergency properties.

. EXAMPLE IV Table ll. The percent effectiveness of each composition is determined by comparing the average time for a 2.0 inch manifold vacuum increase to the average time for a 2.0 inch manifold vacuum increase for a fuel composition containing PTB of DMA-4 which has been assigned an effectiveness of I00 percent.

TABLE ll Additive Concentration. PTB /l Effectiveness so DMA-4 100 c 2 as I The data in Table II show that fuel compositions containing an additive of this invention have improved carburetor anti-icing properties compared to a base fuel and compare favorably to a fuel composition containing a commercially available additive.

EXAMPLE V Fuel compositions are prepared by dissolving additives of this invention in leaded (3 ml. of TEL/gal.) gasoline and in isooctane, and the compositions are subjected to the ASTM D665 and the Mil-250l7-B rust tests. Also subjected to the rust tests are base leaded gasoline and isooctane containing no rust inhibitor. The make-up of each fuel composition and the results of the rust tests are set forth in Table III. The results of the rust tests are expressed in the percent of the surface of a steel test specimen that is covered by rust; each result is the average of two or more determinations.

The data in Table III illustrate the excellent rust inhibiting properties imparted to fuel compositions by the incorporation therein of additives of this invention. In addition to the petroleum hydrocarbon fuels exemplified above, the additives of this invention, when incorporated in fuels such as diesel fuel, jet fuel and burner fuel, yield fuel compositions characterized by enhanced corrosion resistance and improved detergency properties. By the same token, whenthe additives of the instant invention are incorporated in lubricating oils the resultant compositions exhibit improved detergency and corrosion resistance characteristics.

While'the invention has been described above with respect to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

We claim: l. A normally liquid petroleum hydrocarbon compositioncomprising a major proportion of a normally liquid petroleum hydrocarbon selectedfrom the group consisting of gasoline, diesel fuel, jet fuel, burner fuel, and lubricating oil and about 1 to 250 pounds per thousand barrels of a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine having the formula wherein the hydrocarbyl portions of said hydrocarbyl acid orthophosphate each contains from 1 to about 15 carbons, R is a hydrocarbylene group of about 2 to 34 carbons, R is a hydrocarbyl group of about 6 to 30 carbons, and at least about 25 percent of the basic nitrogens of the ditetrahydropyrimidine are converted to the hydrocarbyl acid orthophosphate salt. v

2. A gasoline composition comprising a major proportion of gasoline and about 3 to pounds per thousand barrels of a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine having the formula thousand barrels of a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine having the formula wherein the salt-forming hydrocarbyl acid orthophosphate is a mixture of dilsooctyl acid orthophosphate and isooctyl diacid orthophosphate, R is vinylene, R is tallowyl, and about to about 90 percent of the basic nitrogens of the ditetrahydropyrimidine are converted to the hydrocarbyl acid orthophosphate salt.

l l l I 

1. A NORMALLY LIQUID PETROLEUM HYDROCARBON COMPOSITION COMPRISING A MAJOR PROPORTION OF A NORMALLY LIQUID PETROLEUM HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF GASOLINE, DIESEL FUEL, JET FUEL, BURNER FUEL, AND LUBRICATING OIL AND ABOUT 1 TO 250 POUNDS PER THOUSAND BARRELS OF A HYDROCARBYL ACID ORTHOPHOSPHATE SALT OF A DITETRAHYDROPYRIMIDINE HAVING THE FORMULA
 2. A gasoline composition comprising a major proportion of gasoline and about 3 to 100 pounds per thousand barrels of a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine having the formula
 3. A gasoline composition comprising a major proportion of gasoline and about 3 to 100 pounds per thousand barrels of a hydrocarbyl acid orthophosphate salt of a ditetrahydropyrimidine having the formula 